diff --git a/Cargo.lock b/Cargo.lock
index dfe1a51..1b74c2f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -497,15 +497,6 @@ version = "1.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1c133bc6a41be0d194c306b5506d15e6feeea7b1d6604bd3f8310dfb2ca96486"
 
-[[package]]
-name = "cmake"
-version = "0.1.58"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c0f78a02292a74a88ac736019ab962ece0bc380e3f977bf72e376c5d78ff0678"
-dependencies = [
- "cc",
-]
-
 [[package]]
 name = "cmov"
 version = "0.5.4"
@@ -1672,6 +1663,15 @@ dependencies = [
  "num-traits",
 ]
 
+[[package]]
+name = "num-integer"
+version = "0.1.47"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7ce2d95d4b3734dc35aa2f45e1aa22cd416814592a4f9d9205e11affd5b8e10b"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "num-traits"
 version = "0.2.19"
@@ -1708,15 +1708,6 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "04744f49eae99ab78e0d5c0b603ab218f515ea8cfe5a456d7629ad883a3b6e7d"
 
-[[package]]
-name = "opusic-sys"
-version = "0.7.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c9d1ecdf206421bc74343ab3bb2f30ad2abbfee41fa341f7181fecbaf957769a"
-dependencies = [
- "cmake",
-]
-
 [[package]]
 name = "parking"
 version = "2.2.1"
@@ -1843,6 +1834,15 @@ dependencies = [
  "zerocopy",
 ]
 
+[[package]]
+name = "primal-check"
+version = "0.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc0d895b311e3af9902528fbb8f928688abbd95872819320517cc24ca6b2bd08"
+dependencies = [
+ "num-integer",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.107"
@@ -2005,6 +2005,15 @@ dependencies = [
  "rand_core 0.10.1",
 ]
 
+[[package]]
+name = "realfft"
+version = "3.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f821338fddb99d089116342c46e9f1fbf3828dba077674613e734e01d6ea8677"
+dependencies = [
+ "rustfft",
+]
+
 [[package]]
 name = "redox_syscall"
 version = "0.5.18"
@@ -2190,6 +2199,20 @@ version = "2.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6b1e7f9a428571be2dc5bc0505c13fb6bf936822b894ec87abf8a08a4e51742d"
 
+[[package]]
+name = "rustfft"
+version = "6.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "21db5f9893e91f41798c88680037dba611ca6674703c1a18601b01a72c8adb89"
+dependencies = [
+ "num-complex",
+ "num-integer",
+ "num-traits",
+ "primal-check",
+ "strength_reduce",
+ "transpose",
+]
+
 [[package]]
 name = "rustix"
 version = "1.1.4"
@@ -2651,6 +2674,12 @@ version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6ce2be8dc25455e1f91df71bfa12ad37d7af1092ae736f3a6cd0e37bc7810596"
 
+[[package]]
+name = "strength_reduce"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fe895eb47f22e2ddd4dabc02bce419d2e643c8e3b585c78158b349195bc24d82"
+
 [[package]]
 name = "strict-num"
 version = "0.1.1"
@@ -3223,6 +3252,16 @@ dependencies = [
  "tracing-serde",
 ]
 
+[[package]]
+name = "transpose"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1ad61aed86bc3faea4300c7aee358b4c6d0c8d6ccc36524c96e4c92ccf26e77e"
+dependencies = [
+ "num-integer",
+ "strength_reduce",
+]
+
 [[package]]
 name = "try-lock"
 version = "0.2.5"
@@ -3519,7 +3558,7 @@ dependencies = [
 [[package]]
 name = "waveflow-core"
 version = "1.9.1"
-source = "git+https://github.com/InstaZDLL/WaveFlow?rev=bd8d360cf3db4da946fcd52ec14ed912169c25ec#bd8d360cf3db4da946fcd52ec14ed912169c25ec"
+source = "git+https://github.com/InstaZDLL/WaveFlow?rev=9b50f3de288d62b0ff9f867ab7bda504b255cc5c#9b50f3de288d62b0ff9f867ab7bda504b255cc5c"
 dependencies = [
  "anyhow",
  "async-trait",
@@ -3532,8 +3571,8 @@ dependencies = [
  "image",
  "lofty",
  "md-5",
- "opusic-sys",
  "pinyin",
+ "realfft",
  "regex",
  "reqwest",
  "resvg",
diff --git a/Cargo.toml b/Cargo.toml
index 995fb81..845e927 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -75,7 +75,7 @@ utoipa-scalar = { version = "0.4", features = ["axum"] }
 url = "2"
 uuid = { version = "1", features = ["v4", "v8", "serde"] }
 walkdir = "2"
-waveflow-core = { git = "https://github.com/InstaZDLL/WaveFlow", rev = "bd8d360cf3db4da946fcd52ec14ed912169c25ec", default-features = false }
+waveflow-core = { git = "https://github.com/InstaZDLL/WaveFlow", rev = "9b50f3de288d62b0ff9f867ab7bda504b255cc5c", default-features = false }
 
 [dev-dependencies]
 http-body-util = "0.1"
diff --git a/Dockerfile b/Dockerfile
index 9d1088e..8457045 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -8,9 +8,10 @@ RUN bun run build
 
 FROM rust:1.98-bookworm AS builder
 WORKDIR /build
-# cmake builds the libopus that waveflow-core bundles (`opusic-sys`); the
-# rust image ships a C compiler but not cmake.
-RUN apt-get update && apt-get install -y --no-install-recommends git ca-certificates cmake && rm -rf /var/lib/apt/lists/*
+# No cmake: waveflow-core's libopus decoder sits behind its `opus` feature,
+# which `default-features = false` leaves off. The server decodes through
+# FFmpeg (#282).
+RUN apt-get update && apt-get install -y --no-install-recommends git ca-certificates && rm -rf /var/lib/apt/lists/*
 COPY . .
 # After COPY . ., so the built assets win over any stale local dist/.
 COPY --from=web /web/dist ./webapp/dist